State-of-the-Art Control Solution Propels Wilkins Rogers Mill to the Forefront of Efficient Flour Production, Worker Safety

From cookies and cakes to pretzels and pastries, many of the snack foods enjoyed by consumers along the Eastern Seaboard contain flour milled in the tiny town of Mount Joy, Pennsylvania. Here, the Wilkins Rogers Mills company transforms soft wheat into the key ingredient used by commercial bakers to satisfy America’s sweet and salty cravings.

The Mount Joy mill is one of three plants operated by Wilkins Rogers, whose history dates backs to 1913, when Howard Wilkins and Samuel Rogers purchased a flour mill in Washington, D.C. Aside from the fundamental process of grinding grain and sifting out particles to form a pure powder, today’s industrial flour mills bear little resemblance to their ancestors. Automated processes have transformed the old back-breaking, hand-blistering manual labor required for centuries to extract flour from wheat.

The Mount Joy plant operates two milling units, along with extensive equipment for grain transfer, flour handling, packaging, and bulk shipping. Each milling unit employs massive rollers that separate the wheat’s hard outer coating from the floury inner endosperm. Then comes the process of sieving, sifting and regrinding the flour into different grades, depending on the needs of the bakers who buy it.

The Mount Joy plant can produce up to 700,000 pounds of flour day. But meeting that target became more and more challenging in recent years because of the mill’s outdated control system.

SYSTEM SUPPORT, PARTS AVAILABILITY

The mill’s programmable logic controller (PLC) was vintage1990s. To make changes to the program, operators had to use a laptop computer running Windows 95. Spare parts and support were nearly non-existent and the spare parts that were available were used or remanufactured with no warranties.

Locating replacement parts created even more problems. Operators were constantly searching for parts to keep on hand in case of a shut down. However, the reliability of those spare parts was spotty at best.

The plant’s single human-machine interface (HMI) was also very basic in what was provided for operators in charge of the equipment.

“The computer screen was very old and didn’t give us a good visual representation of the process,” Black said. “Bigger picture, we had difficulty monitoring our plant’s performance and measuring output accurately.” 

“The person who installed the control system in the ‘90s had difficulty supporting it anymore because of the age of the technology,” said Aaron Black, Director of Operations at Wilkins-Rogers.

The question for senior management wasn’t if they needed to invest in new control technology. The question was when. That answer arrived in mid-2015.

GAINS IN EFFICIENCY, SAFETY 

Black and his operations team turned to Kice Automation, well-known for its expertise in the flour-milling business. Wilkins Rogers had consulted with Kice on several smaller projects in its mills.

“No one checked off all the boxes like Kice did,” Black said. “We were well aware of their advanced knowledge and attention to detail.”

Kice’s advanced knowledge in milling processes– including their experience as a Solution Partner within the Rockwell Automation PartnerNetwork™ program -- helped convince Black and his team that instead of a mere replacement, they should implement an entirely new control infrastructure for the Mount Joy facility.

“The Mount Joy team had a wish list of capabilities that couldn’t be realized with just a PLC upgrade,” said Syed Ashraf, vice president of automation/electrical at Kice.

Deploying new sensors for added worker safety was near the top of that wish list.

“We care about employee safety first and foremost,” Black explained. “With new sensors on equipment tied into the control system, we not only enhanced the safety but reduced the chances of equipment failure.”

The Kice team also helped Black meet another key goal: systematically replacing the obsolete control system with little or no downtime in production. That change-over feat required more than six months of careful planning and collaboration between plant personnel and Kice engineers.

“When we were ready to switch out the PLC, we were fortunate that our existing Motor Control Centers (MCCs) had hand-off auto capabilities,” Black said. “That meant we could run all the equipment manually, allowing time for final wiring in the new panels.”